electronics – A Darker View

Favorite Tools

For someone who works with their hands tools are important. We all have our favorite tools, that one we always use as we have for so many years. There may be a dozen screwdrivers in the rack, but that one is used almost every time.

A veteran Weller WES50 soldering station

Thus is with great sadness that I announce the death of my longtime soldering station.

A good soldering iron is a basic tool for an electronics engineer. A multimeter, a soldering iron, and a set of basic hand tools are absolutely necessary for any electronics workbench. To this end I had bought a very good iron, one that has served me well for several decades.

I wonder just how many soldered connections I made with this old soldering iron… Thousands upon thousands certianly, so many circuit boards, connectors, and wires.

There are no available spare parts for this long obsolete soldering station. There are many conversations on bulletin boards and chat rooms lamenting this as others have had their beloved soldering irons fail. The WES50 was long ago replaced by the WES51, and the parts are not interchangable.

With sadness I remove the old soldering station from the bench. I replace it with a new Weller WE1010NA station. I wonder just what work awaits the new soldering iron, how many solder joints will it see in the coming decades. I hope that this new iron will outlast me.

Battery Corrosion Again

Leaking alkaline batteries, the bane of our portable, battery powered existence. All too many times I have found myself repairing electronic devices damage by leaking batteries, or just junking the gear when the damage is too severe.

Corrosion damage in the base section of a Celestron 8SE mount

This time the device in question was just a bit too valuable to dispose of despite fairly extensive damage.

A Celestron Nexstar 8SE telescope.

A Time Capsule Package

In the back of a plastic crate, forgotten for a decade or three, a little cardboard pack holds a few battery holders. A humble package, not containing anything particularly special, yet this is a time capsule from another age, another me from decades ago.

Skin pack holding a set of battery holders from another era. — A set of battery holders in retro packaging

This little package brings back memories… I remember when shelf after shelf of components were packaged this way. The look, the smell, the facination with the fantastic array of parts on display in those little packs, each inspriation for a project or solution. The young teenage me wandering those shelves wondering what I could do with those components.

Midnight Run

The phone rang just as I was going to bed.

This phone call had a number I knew all too well, even without the caller ID showing the name… K1 Remote Operations. A this time of night it would be a problem, a serious problem. This particular problem would have me on the road back to the summit an hour later.

Keck at Night — Looking towards the Keck 2 dome on a moonlit night

Midnight runs to the summit are not common, but they do occur in my life. Usually we can work remotely, the night attendant serving as our remote eyes and hands. Just press the right button, flip the correct switch, done. Not this time. We tried, for over an hour we tried.

I really did not want to head back up. I had just gotten down a few hours ago, having spent the day on the summit working on the usual long list of things that need to get done. Days on the summit, in the thin air of nearly 14,000ft elevation are physically draining.

The irony of this malfunction is that I had seen it before. The dome had tripped out inexplicably on previous occasions. The problem would occur then disappear. Once it vanished you could not troubleshoot it. Unlike most of our other systems there are no logs from the shutter drive, nothing records what was going wrong.

The Friday before this it had happened to me again. But this time was different, I had a maintenance computer attached to the PLC serial port. This time I saw the error, something in the code labeled speed mismatch. No idea what this was, or how it worked. Again the error disappeared, and I could not troubleshoot further as the weather was getting worse. No opening the shutters again.

I needed a chance to figure out what this fault was… Later that day I read through the code, figured out this feature was a speed check to insure that both sides of the shutter are driven evenly. A check to compare the right and left sides of the shutter and to fault if the difference is too large. Two words of memory were compared, if the difference was too large it faulted the shutter drive.

Logic

Flasher Fun

With the Keck Observatory open house approaching I am helping get one of the most popular activities ready. At the last two open houses we have made flasher pins, we will do so again this year.

A simple electronics project… The Flasher Pin

Flashers? These are a simple circuit built on a PCB that flashes a pair of LED’s. Nothing serious, just a bit of electronics fun. The activity allows folks to learn a little electronics and soldering.

The PCB is configured as a pin or badge, with a brooch pin soldered to the back that also serves as a switch to turn on the LED’s.

The original design came from John Maute at SAO. The circuit is based around the venerable LM555 timer IC configured as an astable multivibrator. The LM555 timing circuit is simple enough to solder together in a few minutes, complex enough to look cool and provide a real introduction to an electronic circuit.

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Do you own what you buy?

In this ever complex world in which we live the rules are always changing, and usually getting more complex. A modern, information society has many rules that govern who owns what. Copy a photograph from the web and you are probably breaking the laws concerning copyrights. There is a complex and sometimes contradictory set of laws that governs all manner of ownership in this technological age.

Hay Baler Engine — The engine on a hay baler offers a view of mechanical paraphernalia

Do you know the rules?

Buy a CD with your favorite tunes… Can you copy the tracks onto your phone? Can you create a video with the music and post it to YouTube? What about that expensive photo software package? Can you put it on your laptop and desktop? The rules are often complex, and often the answer is not clear cut.

Increasingly we do not actually own what we buy. At least that is what many corporations will tell us.

You would think that the answer is easier if the thing we are talking about is a physical object. If you buy a car, can you re-paint it, install a new stereo, or ignition system. Of course you can do that. Can you? Sometimes the answer is no.

Increasingly corporations attempt to maintain control of a product after the sale. They use many tools to do this. One is intellectual property, copyrights and copy protection on the software that is now embedded into many of the things we buy.

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Service Call

It does not happen very often, but it does happen. Driving up to the summit in the night to fix the telescope. As an operations engineer it is part of the job, but I can think of only a handful of times in my decade on the summit I have actually done it.

The motor controllers for the Keck 2 top shutter

Considering it takes the better part of two hours to get to the summit there is no point in trying unless the issue occurs early. You have to consider the issue… Can you fix it in the middle of the night? Will there be any night left once you fix it? Do you just call the night and head up the next day with a full crew and a good night’s rest to fix it properly?

This particular problem was discovered first thing upon opening. Well? Lack of opening for the night. The top shutter on Keck 2 would not move, fault lights all over the place. Hard to look at the sky with the top shutter closed. I worked the issue over the phone for a while with Nick as far as we could.

The conclusion? I would have to work the problem in person to fix it, I have to go up.

Can I fix this? Probably. I found myself leaving the house before 9pm for a run to the summit.

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Perfboard

I was looking at some photos and realizing how much perfboard I have used in recent years. I routinely find myself building small circuits, and that process almost always begins with grabbing a bit of perfboard from the supply stash.

Perfboard is the basis of point-to-point wiring and has been around since well before I started in electronics as a young teenager. It is generally a small circuit board with holes drilled in a 0.1″ grid.

The holes are usually about 0.042″ and will accommodate a wide range of electronic components without modification. Cheap perfboard will have no copper pads or traces, good perfboard will have a pattern of copper traces and pads to which you can solder your components. Better yet is perfboard with plated-thru holes and pads on both sides.

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GenPIC Second Code Release

A minor code revision as I slowly get everything working properly. I am adding new modules as I need them for other projects.

GenPIC Processor — The microprocessor on a GenPIC PCB assembly

The latest GenPIC deployed will be a coolant valve controller that allows remote control of some glycol valves in the AO bench. It is a pretty simple device, just four relays with some automatic timing rules and a serial control interface.

In the process I added support for the service connectors including parallel and simple serial modules to the GenPIC code base, may as well release it. Thus you get code release 0.2…

GenPIC Code 0.2

Along with the new modules I removed the copyright notices that I had left in the code, replacing them with a Creative Commons Attribution-ShareAlike 4.0 (CC BY-SA 4.0) license, just something I overlooked when releasing everything as open source.

Next up will probably be SD card support, I have a project that needs to be finished requiring some reasonable data storage. Just ordered a few micro-SD card breakout boards from SparkFun